The invention relates to cameras and photographic equipment and more particularly relates to a lens cowl mount and camera.
Many cameras use interchangeable lenses that are attached to the camera body by a bayonet mount. To install an interchangeable lens using a typical bayonet mount, the lens is moved toward the camera body in a direction parallel to the optical axis until claws on the lens pass through matching slots adjoining a lens opening in the camera body. The lens is then rotated until it locks into place. This is quick and much more convenient than an alternative: screwing a lens onto a camera body having matching screw threads.
The claws of a bayonet mount typically have a shape that is complementary to the shape of the slots. Other claw and slot shapes can be provided to meet particular purposes, as disclosed in U.S. Pat. No. 4,199,248; U.S. Pat. No. 4,307,954; and European Patent Publication EP 0 788 021 A1. Examples of locking mechanisms that hold the lens in place after attachment, are disclosed in a U.S. Pat. Nos. 4,302,077 and 4,478,492. Many interchangeable lenses include a manual zoom feature, in which a zoom ring is rotated to change the focal length of the lens. The zoom ring is typically held on the rest of the lens unit by a fastener or is trapped by another part that is held on by a fastener or the like. See U.S. Pat. Nos. 5,255,939 and 6,349,003. Such attachment methods are effective, but tend to add parts and complexity to assembly procedures.
Mounts that hold interchangeable lenses have to provide for accurate positioning of the lenses. Zoom rings do not need such accurate positioning, but do need to be able to rotate relative to the rest of the lens units.
It would thus be desirable to provide camera and mount assemblies having the convenience and simplicity of a bayonet mount, but allowing rotation of one part relative to another.
The invention is defined by the claims. The invention, in broader aspects, provides a cowl assembly that has a base and a twist ring mounted to the base. The twist ring defines an axis. The twist ring is rotatable relative to the base about the axis, between a primary orientation and a secondary orientation. A cover is removably attached to the base. A cowl is coupled to the cover. The cowl engages the twist ring. The cowl is pivotable with the twist ring between the primary and secondary orientations. The twist ring blocks the cowl from pivoting beyond the primary and secondary orientations to an overtravel orientation, in which the cowl is freely removable from the cover.
It is an advantageous effect of the invention that improved camera and mount assemblies are provided that have the convenience and simplicity of a bayonet mount, but allow rotation of one part relative to another.